Question

Study the cross given below:

Identify the abnormalities ‘1’ and ‘2’ in the offsprings of a cross done between a couple and distinguish between them.

Hint:

Turner’s syndrome (XO) results in 45 chromosomes (female), while Klinefelter’s syndrome (XXY) results in 47 chromosomes (male). These are chromosomal disorders caused by non-disjunction during gamete formation.

Answer 1

Offspring 1: Turner’s Syndrome (45, XO)
Caused due to absence of one X chromosome (Monosomy).
Genotype: 44 + XO (total 45 chromosomes).
Phenotype: Female with underdeveloped secondary sexual characters, short stature, and sterility. Offspring 2: Klinefelter’s Syndrome (47, XXY)
Caused due to the presence of an extra X chromosome (Trisomy).
Genotype: 44 + XXY (total 47 chromosomes).
Phenotype: Male with feminine body features, gynecomastia, and sterility.